).Erik, I'll let you figure out which unit to replace by its Banzai equivalent and where (it should for sure concern several scenarios). Meanwhile I'll carry on my tests with the version at my disposal (i.e. without Banzai units).
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03Gavutu:
Great scenario, but I think there are several things to adapt here and there (like about CPs)... 'can be challenging timewise, but that's fine (of course!)...
Anyway, first things first:
-> In this scenario, as it's about "Marine Airborne units",
I suggest to "offer" a core unit to the player: a paratrooper unit, a core US Airborne '42"!Maybe with the historical name (mentioned within scen descr) "1st Marine Parachute" (Battalion), or something...
Like this, the core roster continues to be built up sticking relatively close to History... But then, things have to be balanced. Therefore, now I suggest for 02Tulagi1 (where it's historically about "Marine Raiders") to "offer" not only one but two units to the player: 2 core units of "Marine Raiders"! 
(Balanced? Yeah, look:
1 Airborne ('42) = 100 RPs & 4 LCPs;
1 Marine Raider (but not the '43 version, of course!
) = 50 RPs & 2 LCPs => 2 Marine Raiders "=" 1 Airborne unit in terms of RPs and LCPs... so, that's indeed balanced!
)So, like this, the player can make either choice at the crossroad, then he (or she) will receive just directly after one or two new core units (the same concept has been applied within the great Winter Wars campaigns).
->
Of course, briefing to add... here as well a cool and immersive one would definitely be welcome... here, as I see it, this briefing should be in several parts, while moving the cam/focus using first infos of the scen description (two "islands", but we'll focus on the first and battle for it), then few nice words about current objectives... -> Speaking of objectives: As sec obj, capture "Hill 121" on Tanambogo?!
NO!
( ) No way, that's for the very next scenario!(And this hill is supposed anyway to be very well defended and fortified...)
1. Now, to have a sec obj with this very same reward, 'could be replaced by this
"sink at least one enemy submarine"? (There is only one, I know, but the player hasn't this info, in principle! )2. And there is another "consequence" about the other sec obj: "Eliminate all enemy HMG units"... this scenario can be already a little challenging timewise (many Jap land reinforcements - but that's fine!), we shouldn't bother about Tanambogo now... the point is that one of the 4 HMG units is blocking the entrance way at Tanambogo!
So, two options: a) Replace this unit with some regular infantry (so no longer any HMG here), or b) Change this obj into "Eliminate at least 3 enemy HMG units" (triggers included!)... That's your pick! -> We've 9 ACPs to purchase some core planes... so far, so good... BUT:
1. To balance things, we've not any plane right now (core or not) in the two Tulagi scenarios...
2. The next scen of this (crossroad's) branch has 9 ACPs as well, but the following scenarios (at least the first ones) have no ACP at all... so we can't use these core planes during at least several scenarios...
These two points lead me to suggest you to replace this by AUX planes!9 ACPs = 3 planes, so what about a "classical" carrier formation of 1 Dauntless, 1 Avenger and 1 Wildcat? (so 2 bombers and 1 dogfighter)
Another element in favor of this is we've air exits without return
(but we're warned and the scenario is relatively short timewise anyway, so it's perfectly fine!).Immersively fine as well, as carrier group should have to move back to carrier at some point.
->
Some (re)deploy hexes should be added somewhere... after deployment phasis we could have still some LCPs unused & we may have some losses, i.e. units to redeploy, 
so...-> Still about CPs, but now LCPs:
The scenario start with a +1035 RPs & 53 LCPs... 53 LCPs?
That's a lot compared to the start of the campaign and that may be too much if we compare it to the LCPs of the "Tulagi-branch", where it was 22 and 28 LCPs at start of scenario(s), so less than 30...
The next scen (05Tanambogo) has many LCPs as well, then (this time out of the crossroad branches) after two "shorter" scenarios (shorter in terms of RPs, but they do seem awesome and add really some variation to this campaign), at 08Ilu1 we're back to 31 LCPs at start... again around 30, more closer to the "Tulagi-branch" LCPs...
If we've much more LCPs now, we'll purchase many units... but won't be able to use them for a while anyway...
To make the scenarios of this Gavutu/Tanambogo-branch more "adapted" to this campaign, I suggest to remove about 20 LCPs and to add more or less the equivalent in terms of auxiliary units (to prevent unbalancing all ), without forgetting to reduce accordingly the "+1035 RPs" from start (as we've less to purchase like this)! ->
Add an aux US DD near the last wave to help dealing with the enemy sub, especially if there is an obj about this enemy sub. Anyway, like this our cruiser could focus more on supporting land troops on... land!
-> The income seems a little low to me within this scenario (once all RPs have been spent during deployment phasis)...
a few more RPs/turn would be nice here (at least after the first half of the scen)! -> Well, add the name at the northern islet flag: Gaomi!
-> An Japanese seaplane base is mentionned within the scenario description, which looks definitely interesting!
But... there is no "Seaplane Base" on the map right now!?
So, something to add!
Perhaps with a new (sec) obj? -> Very little details at scen descr: "[...] followed by [instead of "be"] B and C companies. [...]" & at the very end, add a point or something...
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05Tanambogo:
I’ve achieved a Major Victory on the 21st turn out of 28, so this one isn’t challenging timewise as was the previous one. But this may change a little with the apparition of some real “Banzai” opponents!
Anyway, let’s debrief, shall we?
-> First, directly same considerations:
1. Reduce our starting LCPs (to around 20, yes, as we'll have reinf on t3 with some of our own core units
) AND replace the LCPs you'll remove by auxiliary units (we'll come back to it really soon!) ;2. Add the name Gaomi on the 3rd islet (with a flag);
3. Add the “Seaplane Base” (either still Japanese or not, it depends);
4. Add some cool and immersive briefing (it doesn’t need to be too long, but it’s definitely better to have one);
5. Remove the 9 ACPs but give us 3 auxiliary planes (maybe the same trio?);
6. I still find the income to be a little low…
-> In the scen descry, one can read: “[…] This time the Marines had support of two light tanks which landed on Tanambogo with […]”
Perfect, so as auxiliary unit, give at least to the player some light tank! (Besides, you’ve put the single Japanese AT-unit of this map near the landing area, so give the AI a chance to make the best use of it… thus enhancing as well the challenge for the player!
)(By the way, don't forget to put some auxiliary units both almost ready to land AND on land, on the Gavutu side as well!)
-> Pri obj description: Add the info that the player will have time to try completing sec obj!
-> Write down some names on this map, at the different flags!
->
Cool, a special event on t3… but… no title, no picture, no text… probably about reinforcements (or, but less likely, about Gaomi?)… picture name “higgins” on the Editor… hem… definitely something to complete! 
( )And… for now I think it’s more or less all about these two scenarios…
Et voilà !
But, I think its really too difficult to achieve it right now, and I've encountered an issue: whatever happened, the pri obj was always considered as achieved!? 
Another little thing to fix.